There has been an automated screen correction device for automatically displaying a screen corresponding to a change in ambient light in portable terminals such as mobile terminals and car televisions. This automated screen correction device is equipped with a sensor for measuring the ambient light and outputting an illuminance value, which is ambient environment information. With this structure, the automated screen correction device reads out a brightness adjustment value corresponding to the illuminance value measured by the sensor from a memory. Then, the automated screen correction device sets an optimum illuminance value for the user to a display unit based on calculation of the adjustment value read out and information on display screen mode selected by the user. (For example, refer to Patent Literature 1.)
A conventional brightness correction device, such as this automated screen correction device, determines that the current brightness has changed to a different brightness if, for example, other brightness levels are detected for a predetermined number of times in the current brightness, so as to detect that the brightness has changed. The predetermined number of times is, for example, 50 times.
However, the above conventional brightness correction device frequently changes brightness of display unit due to sensitive reaction to changes in ambient light if light and dark of ambient light significantly changes such as when a car television equipped with this brightness correction device passes through a place where brightness changes again and again, typically a tree-lined street. This results in giving a sense of discomfort to the user.
[Citation List]
[Patent Literature]
[PTL 1] Unexamined Japanese Patent Publication No. 2000-082137